Building structures, particularly tall urban buildings, were typically washed manually. In manual washing, a scaffolding structure would be suspended from the top of the building to be washed. The scaffolding can be raised or lowered so that a person standing on the scaffolding can wash the windows and exterior surfaces of the building by hand. After a vertical section of the building is washed, the scaffolding is repositioned laterally so that the next adjacent vertical section of the building may be cleaned. This procedure was repeated until the entire building was washed. This and other methods of manually cleaning windows of a building have proven to be extremely time consuming and labor intensive.
Manual washing of buildings is also unacceptably dangerous. Equipment can fail and fall. Operators can misuse the equipment and fall. And environmental conditions, such as wind and precipitation can make the cleaning operations more dangerous or even impossible. Thus, insurance rates for manual cleaning operations can comprise a significant portion (e.g. 40%) of labor costs.
To address the aforementioned problems, various types of automated window washing devices have been developed. For example, U.S. Pat. No. 7,665,173 discloses one such automated window washing device. The entirety of U.S. Pat. No. 7,665,173 is hereby incorporated herein by reference. However, the device shown in this patent is relatively large and heavy. This means that the apparatus must be transported in a large commercial size vehicle and there must be a team of operators to operate the device. It also requires rigging capable of lifting at least 2000 pounds. Thus it is best suited only for use on very large buildings such as skyscrapers. The power requirements of such large devices are also significant, which requires a dedicated power cable (typically 220V) to be connected the device. Additionally, this large and complex device is very expensive.
Other issues and disadvantages of conventional automated window washing devices such as that in U.S. Pat. No. 7,665,173 include: heavy weight (e.g. 600 lbs.); too large to fit into a pickup truck; must use uses fans and weights to hold against building; takes 2 people all day to setup—heavy and hard to move; travels approximately 35 feet per minute; high cost for the large and complex machine; suited only for taller buildings so limited market opportunity; high volume cleaning solution use (e.g. 4 gallons per minute); complex and expensive rigging; typically uses 5/16″ wire rope (heavy); heavy winch—120 lbs.; have on-board deionizing filter with 220 volt motor, which adds weight and complexity; heavy and welded frame contributes to high device cost and weight; requires ¾″ water line; and uses noisy stabilizer fans.
Therefore, there is an ongoing need to provide a compact and easily portable automated window washing device, system, and method for the same that addresses, at least in part, the above-mentioned drawbacks of the conventional devices.